AB1014 RADIOGRAPHIC VERSUS NON-RADIOGRAPHIC AXIAL SPONDYLOARTHRITIS: RESULTS FROM TREASURE DATABASE
Authors: L. Kiliç, G. Ayan, P. Atagündüz, S. Akar, N. S. Yasar Bilge, E. Dalkiliç, Y. Pehlivan, O. Küçükşahin, C. Bes, M. Çinar, H. Emmungil, D. Ersözlü, A. Ates, R. Mercan, G. Kimyon, S. S. Koca, E. Gönüllü, V. Yazisiz, N. A. Kanitez, A. Erden, B. N. Coşkun, B. Yağiz, T. Kaşifoğlu, S. Kiraz, U. Kalyoncu, A. İ. Ertenli
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Axial Spondyloarthritis is an umbrella term including radiographic (r-axSpA) and non-radiographic (nr-axSpA) forms which has been initially suggested by Assessment of SpondyloArthritis International Society (ASAS) as a different stages of the disease. Within time, studies have tried to answer whether these two entities represent distinct features, and the debate is still ongoing. <h3>Objectives</h3> The objective of this study is to define the similarities and differences of r-AxSpA and nr-AxSpA patients using a large national registry data. <h3>Methods</h3> TReasure is a national, multicentre, longitudinal, and observational database, initiated in Turkey in 2017 [1]. This database included patients with inflammatory arthritis, rheumatoid arthritis, axial-and peripheral SpA at the time of the first introduction of biological treatment. At the time of this analysis database consisted of 7015 SpA patients. All patients registered to the database fulfill the 2009 ASAS classification criteria. For this analysis, patients were categorized into r-AxSpA and nr-AxSpA and demographic and clinical characteristics of patients were determined. <h3>Results</h3> There were 4629 (86.7%) patients with r-AxSpA, 707 (13.3%) patients with nr-AxSpA patients. <i>Demographic differences</i>; r-AxSpA group were older (45 (16) vs 41 (14), p&lt;0.001) and male predominant (59.6% vs 46.0%, p&lt;0.001), with longer disease duration at bDMARD initiation (3.0 (6.9) vs 1.1 (3.4) years, p&lt;0.001) and more smoker (61.4% vs 50.4%, p&lt;0.001). <i>SpA clinic/genetic differences</i>; r-AxSpA group had less arthritis (7.7% vs 27.5%, p&lt;0.001), heel pain (11.1% vs 40.8%, p&lt;0.001), dactylitis (3.4% vs 8.1%, p&lt;0.001), psoriasis (10.2% vs 14.5%, p&lt;0.001), SpA family history (28.2% vs 40.8%, p&lt;0.001), IBD (4.5% vs 7.4%, p=0.001) and more HLA-B27 positivity (58.2% vs 51.4%, p&lt;0.001), similar uveitis rate (13.2% vs 14.8%). <i>SpA Outcome measures (bDMARD baseline) differences;</i> r-AxSpA group had worse functionality and quality of life measured by BASFI (5.0 (3.0) vs 4.0 (3.9), p&lt;0.001), HAQ-DI 0.63 (0.40) vs 0.55 (0.65), p=0.029) respectively. Worse metrology by BASMI 3.2 (2.6) vs 1.7 (2.1), p&lt;0.001) and high disease activity by ASDAS-CRP (3.64 (1.28) vs 3.24 (1.33), p&lt;0.001) with higher CRP (12 (21.8) vs 7.3 (15.0) p&lt;0.001) was observed. <i>SpA imaging differences;</i> r-AxSpA group had higher rate of `any syndesmophytes `(26.6% vs 5.4%, p&lt;0.001), hip involvement (24.6% vs 4.5%, p&lt;0.001), hip prosthesis (2.3% vs 0.3%, p&lt;0.001), MRI structural lesions (63.6% vs 37.3%, p&lt;0.001), and less active MRI lesions (74.6% vs 87.0%, p&lt;0.001). No significant difference was observed in the physician decision on the b-DMARD choice at baseline (p=0.673). <h3>Conclusion</h3> A significant proportion of SpA patients who were initiated bDMARD have r-SpA. Although the two entities are seen as the continuum of each other, they have significant differences in terms of demographic, clinical, genetic, functional, metrology, activity and imaging characteristics. On the other hand, there is no difference in treatment choices at the stage of bDMARD initiation. <h3>Reference</h3> [1]Kalyoncu U, et al. Turk J Med Sci. 2018 Aug 16;48(4):856-861. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.